This application claims the priority of German Patent Application No. 198 01 172.5-14, filed Jan. 15, 1998, the disclosure of which is expressly incorporated by reference herein.
The invention relates to a seat, particularly a vehicle seat having an air-permeable, cubical cushion.
In the case of a known vehicle seat as described in German Patent Document DE 27 04 666 A1, the edge part of the seat is formed of a frame produced from an integral foam in which a cut textile is foamed in close to its upper edge on the edge side which covers the surface. Below the cut textile, the frame is filled with a foamed-material body made of polyurethane (PUR). The foamed-material body is supported on a wall by means of its bottom side facing away from the cut textile. The frame is fastened on a surrounding outer profile of the wall. In the case of forward control vehicles, the wall may be constructed as a tin tub directly machined out of the vehicle body floor. Such a vehicle seat can be simply manufactured in a low-cost manner without a seat cover. However, this type of vehicle seat does not provide sufficient seating comfort since the integral foam of the frame has no significant cushioning elasticity and exercises a lateral pressure on the sitting person which is unpleasant.
In the case of a vehicle seat as described in European Patent Document EP 0 386 890 A1, the cushioning is composed of a load-absorbing seat cushion and a load-absorbing back cushion, on which two side cushions are fastened on the left and on the right respectively. The lateral parts are shaped with edge beads and are made of a foamed material which has a larger density than the foamed material of the seat cushion and the back cushion. This higher density foamed material of the lateral parts ensures a higher lateral stability with a simultaneous flexibility in the case of rotating movements of the person sitting in the vehicle seat.
In the case of a known vehicle seat of the initially mentioned type, in U.S. Patent Document U.S. Pat. No. 4,259,896, the inner cushioning body consists of an air-permeable material. The edge part which surrounds the cushioning body consists of a non-permeable material that is covered by a cushion covering made of an air-permeable material. A box is arranged on the underside of the air-permeable cushion support, which is constructed as a flat bucket. The box is constructed such that air flowing into it is deflected toward the cushion body and thus ventilates the air-permeable cushion body through the cushion support.
In the case of a cushion support for a vehicle seat as shown in German Patent Document DE 93 06 999 U1, it is known to construct the cushion body of different layers, which includes a layer made of an air-permeable nonwoven material.
In the case of these known seat cushion for vehicle seats, the seat cushion is composed of two different foam qualities. In this case, a soft center part is adjoined on the left and the right by two cheeks made of a harder foamed material and are glued to the center part (Freitag "Vehicle Seat made of Chemical Materials", Kunststoffberater 1982, Page 23-26).
Finally, as illustrated in German Patent Document DE 36 09 095 A1, it is known to construct a duct between the backrest cushion and the backrest rear wall to provide an air flow, thereby increasing the sitting comfort in the case of vehicle seats. As the result of a suitable, air-permeable construction of the backrest cushion, air flowing through the duct removes water vapor forming on the cushion surface when the seat is occupied.
The present invention is based on the object of providing a seat of the aforementioned type which provides optimum seat pressure distribution as well as air-conditioned sitting comfort. Simultaneously a reduction of the proportion of manual work required for high-quality seats is achievable during the manufacturing of the seat.
The seat according to the invention has the advantage that, as the result of the selected cushion materials, in the occupied condition of the seat, the cushion contours, interacting with the cushion elasticity, are optimally adapted to the body shape of the respective seat user. The division of the cubical cushion body having a very simple geometrical shape and the foamed-to-shape edge part having complicated shapes of the edge beads, results in a reduction in manual work expenditures on the cushion body made of a nonwoven material, thereby achieving a considerable lower cost for the manufacturing the seat. The air-permeable construction of the cushion support, in conjunction with the nonwoven material, permits good ventilation of the seat by means of existing air so that the air conditioning of the seat is also found to be very comfortable.
The cushion designed according to the invention is preferably used as a seat cushion and a backrest cushion which will then rest on an air-permeable cushion support fastened on the seat frame, on the one hand, and on the backrest frame, on the other hand.
Advantageous embodiments of the seat according to the invention with expedient further developments of the invention are contained in the additional claims.
According to a preferred embodiment of the invention, the fibers of the air-permeable nonwoven material extend perpendicularly to the top side of the cushion body. This significantly increases air permeability of the cushion body.
Latexed plant fibers, such as coconut fibers, latexed animal hair or mechanically or chemically/thermally connected textile fibers, such as wool, are preferably used as the nonwoven material. The cushion body may consist of several different layers of the above-mentioned nonwoven materials which are situated above one another and between which spacing knits may also be arranged.
In order to achieve a particularly pronounced surface softness, according to another embodiment of the invention, a thin layer of an open-pored and/or perforated cut foam is placed on the top side of the cushion body.
According to an advantageous embodiment of the invention, in the case of a vehicle seat with a seat cushion and a backrest, the cushion designed according to the invention is arranged in the seat cushion area as well as in the backrest area. A hollow space, which adjoins the cushion support and extends over the backrest is provided in the backrest. The hollow space has one opening respectively on or close to the bottom or top side of the backrest. On the bottom side of the backrest, at least one air guiding element is arranged. The air guiding element is constructed such that air from an air conditioning or heating system of the vehicle flowing along under the seat cushion is introduced at least partially into the hollow space. As the result of the air flow along the cushion support of the seat cushion and through the hollow space along the cushion support of the backrest and exiting on the top side of the backrest, good physiological air conditioning characteristics of the cushion construction according to the invention can be exhibited.
According to another embodiment of the invention, a ventilator may be provided for promoting the air movement. The ventilator may be arranged either under the seat cushion or on the underside of the backrest close to the opening of the hollow space.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.